After checking logs, I've found that my router was causing the problem (Philips 11G-ADSL). Attempting to connect using command line parameters causes it to log "UDP Flood to Host", while connecting from the in-game browser does not. Turning off one of its firewall features fixes this issue.

On the off-chance somebody else with the same horrible router finds this, you need to disable "SPI and Anti-DoS firewall protection", at Firewall -> Intrusion Detection.

I do not know exactly what the criteria used by the router to detect a DoS are.

Can anybody shed any light on how Arma's network behaviour varies between connections from the in-game browser and connections via -connect?

I do believe I was TKed by the same player. I think the nick was chosen expressly to be difficult to kick.

I hope the current system is a placeholder - in Arma 2, one can vote from a graphical list (Map -> Server control) as well as with "#vote kick username", and this problem would be fixed completely by implementing a similar graphical voting dialogue in A3.

I would like to know how you know that - BLUFOR represents various NATO forces, and Israel is not a NATO member.

The only connection I can see here is that the TRG-20/21 are modelled on an Israeli weapon (the TAR-21), but at least currently they seem to be OPFOR weapons.

As for the actual issue of female soldiers, there are already a large number of posts about that, but bugs about missing units seem a bit odd. There are also no tanks or fixed-wing aircraft, for example, and I thought it was obvious that the Alpha contains a subset of the units that are planned for Arma 3.